Risk Factors for the Mortality of Pneumocystis jirovecii Pneumonia in Non-HIV Patients Who Required Mechanical Ventilation: A Retrospective Case Series Study

Association between the cumulative dose of glucocorticoids before the development of pneumonia and death in patients receiving long-term glucocorticoids: a secondary analysis based on a Chinese cohort study

Background

The present study aimed to evaluate the association between the cumulative dose of glucocorticoids (GCs) and case fatality in hospitalized patients who developed pneumonia while receiving glucocorticoid therapy.

Methods

This retrospective cohort study included 625 patients receiving long-term GC treatment who were hospitalized with pneumonia (322 male and 303 female). Data were obtained from the Dryad Digital Repository and were used to perform secondary analysis. Multivariable Cox proportional hazard regression model and restricted cubic splines (RCS) were used to evaluate the association between the cumulative dose of GCs and case fatality. Sensitivity analyses and subgroup analyses were performed.

Results

The 30-day and 90-day death rates were 22.9 and 26.2%, respectively. After adjusting for potential confounders, compared with those in the lowest quintile (≤ 1.5 g), the Cox proportional hazard regression model analysis showed that patients with different cumulative doses of GCs (1.5 to 2.95, 2.95 to 5, 5 to 11.5, and > 11.5 g) had lower risks for 30-day death, with respective hazard ratios of 0.86 (95% CI, 0.52 to 1.42), 0.81 (0.49 to 1.33), 0.29 (0.15 to 0.55), and 0.42 (0.22 to 0.79). The multivariable-adjusted RCS analysis suggested a statistically significant N-shaped association between the cumulative dose of GCs and 30-day death. A higher cumulative dose of GC tended to first lead to an increase in 30-day death within 1.8 g, then to a statistically significant decrease until around 8 g [HR for 1 g = 0.82 (0.69 to 0.97)], and again to an increase afterward. Similar results were found in the subgroup analyses and sensitivity analyses.

Conclusion

N-shaped association between the cumulative dose of GCs and case fatality was observed in patients receiving long-term GC treatment who were hospitalized with pneumonia. Our findings may help physicians manage these patients.

Risk factors of pneumothorax and pneumomediastinum in COVID-19: a matched case-control study

BACKGROUND

During the novel coronavirus disease-2019 pandemic, a considerable number of pneumothorax (PNX)/pneumomediastinum (PNM) associated with COVID-19 have been reported, and the incidence is higher in critically ill patients. Despite using a protective ventilation strategy, PNX/PNM still occurs in patients on invasive mechanical ventilation (IMV). This matched case-control study aims to identify the risk factors and clinical characteristics of PNX/PNM in COVID-19.

METHODS

This retrospective study enrolled adult patients with COVID-19, admitted to a critical care unit from March 1, 2020, to January 31, 2022. COVID-19 patients with PNX/PNM were compared, in a 1-2 ratio, to COVID-19 patients without PNX/PNM, matched for age, gender, and worst National Institute of Allergy and Infectious Diseases ordinal scale. Conditional logistic regression analysis was performed to assess the risk factors for PNX/PNM in COVID-19.

RESULTS

427 patients with COVID-19 were admitted during the period, and 24 patients were diagnosed with PNX/PNM. Body mass index (BMI) was significantly lower in the case group (22.8 kg/m² and 24.7 kg/m²; P = 0.048). BMI was statistically significant risk factor for PNX/PNM in univariate conditional logistic regression analysis [odds ratio (OR), 0.85; confidence interval (CI), 0.72-0.996; P = 0.044]. For patients on IMV support, univariate conditional logistic regression analysis showed the statistical significance of the duration from symptom onset to intubation (OR, 1.14; CI, 1.006-1.293; P = 0.041).

CONCLUSIONS

Higher BMI tended to show a protective effect against PNX/PNM due to COVID-19 and delayed application of IMV might be a contributive factor for this complication.

Risk factors for Pneumocystis pneumonia with acute respiratory failure among kidney transplant recipients

PURPOSE

One of the rare life-threatening fungal infections is pneumocystis pneumonia (PCP). Immunocompromised patients are the main vulnerable population. We investigate the risk factors associated with the development of severe PCP infection with acute respiratory failure after kidney transplantation.

MATERIALS AND METHODS

This is a retrospective, single-center, case-control study. PCP patients who are kidney transplant recipients and required high-flow oxygen support or mechanical ventilation between March 2009 and February 2017 were included in the study. The comparison was conducted between the non-severe and severe PCP groups. To identify associated risk factors, we performed univariate and multivariate logistic regression.

RESULTS

Among the total 2,330 kidney transplant recipients, 50 patients (2.1%) were diagnosed with PCP. Of these, 27 patients (54.0%) had severe PCP and 7 patients (14.0%) died, all of them were severe PCP patients. In the severe PCP group, the time from transplantation to PCP diagnosis (23.4 ± 24.9 months vs. 13.7 ± 9.9 months, p = 0.090) was insignificantly faster than in the non-severe PCP group. According to multiple logistic regression analysis, the significant risk factors associated with severe PCP were as follows, age (odds ratios (OR) 1.07; 95% confidence intervals (CI): 1.01-1.13; p = 0.027), time from transplantation to PCP diagnosis (odds ratios (OR) 0.92; 95% confidence intervals (CI): 0.86-0.99; p = 0.024), lymphopenia (OR 6.48; 95% CI: 1.05-40.09; p = 0.044), and history of acute rejection within 1 year (OR 8.28; 95% CI: 1.29-53.20; p = 0.026).

CONCLUSION

Patients who have lymphopenia at the time of hospital admission or have been recently treated with acute rejection are more likely to progress to severe PCP, requiring intensive monitoring and aggressive treatment.

Development and Validation of a Diagnostic Nomogram for Pneumocystis jirovecii Pneumonia in Non-HIV-Infected Pneumonia Patients Undergoing Oral Glucocorticoid Treatment

Purpose

Pneumocystis jirovecii pneumonia (PJP) is an opportunistic but potentially fatal infection with increasing prevalence in HIV-free patients. Glucocorticoid therapy is one of the most important risk factors for PJP. The delay in diagnosis contributes to poor outcomes. Hence, the aim of this study was to develop and validate a nomogram for the diagnosis of PJP in patients with non-HIV-infected pneumonia who are undergoing oral glucocorticoid treatment.

Patients and Methods

This study was a retrospective, cross-sectional research. The development group included 434 patients who were admitted with pneumonia from 6 hospitals. Demographics, symptomatic features, laboratory and computed tomography data were analyzed using the least absolute shrinkage and selection operator (LASSO) to select potential diagnostic indicators. Binary logistic regression was used to develop a diagnostic nomogram. Another 119 patients with pneumonia admitted at Sichuan Provincial People's Hospital was used as the validation group. The diagnostic performance of the nomogram was measured by area under the receiver-operating-characteristics curve (AUC), calibration curves, and the net benefit by decision curve.

Results

PJP prevalence was 25.3% in the development group. LASSO regression revealed that age, lymphocyte count, fever, dry cough, respiratory failure, ground-glass opacity in lungs, glucocorticoid therapy duration, and immunosuppressive therapy were indicators of PJP. The nomogram showed robust discrimination, with an AUC of 0.82 (95% CI 0.77-0.86) in the development group and an AUC of 0.87 (95% CI 0.80-0.94) in the validation group, both showing acceptable calibration. In the decision curve analysis, our model consistently achieved a greater net benefit across almost all ranges of clinical thresholds.

Conclusion

We developed a nomogram with good diagnostic power for PJP diagnosis in pneumonia patients receiving oral glucocorticoids. This nomogram may help promote timely treatment of PJP and thus reduce the mortality rate in these patients.

Outcomes and Risk Factors for Mortality in Pneumocystis Pneumonia Patients with Rheumatoid Arthritis: A Multicenter Retrospective Cohort Study

OBJECTIVE

To evaluate outcomes and risk factors for death in patients with rheumatoid arthritis (RA) who developed Pneumocystis pneumonia (PCP).

METHODS

: We included RA patients who were diagnosed with PCP at seven participating community hospitals between July 2005 and October 2020. Clinical features were compared between survivors and non-survivors. Disease-modifying antirheumatic drugs (DMARDs) before PCP onset and after PCP recovery were also examined.

RESULTS

Seventy RA patients developed PCP, and among them, 60 (85.7%) received methotrexate (MTX) monotherapy (40%) or MTX combination therapy with other DMARDs (45.7%). PCP was more likely to occur after 12 months of MTX monotherapy and within 3 months of MTX combination therapy. Thirteen patients (18.6%) died despite PCP treatment. Multivariable logistic regression analysis revealed that coexisting RA-associated interstitial lung disease (RA-ILD; odds ratio [OR] 6.18, 95% confidence interval [CI] 1.17-32.63) and delayed PCP treatment with anti-Pneumocystis drugs (OR 15.29, 95% CI 1.50-156.15) are significant risk factors for PCP mortality in RA patients. Most survivors successfully resumed DMARD therapy without PCP prophylaxis; one recurrent PCP case was observed during follow-up (median, 4.1 years).

CONCLUSION

To avoid a treatment delay, RA patients should be followed-up for signs and symptoms of PCP development, especially those with RA-ILD.

Diagnostic Value of Bronchoalveolar Lavage Fluid Metagenomic Next-Generation Sequencing in Pneumocystis jirovecii Pneumonia in Non-HIV Immunosuppressed Patients

Introduction

This study aims to assess the value of metagenomic next-generation sequencing (mNGS) of bronchoalveolar lavage fluid (BALF) in the diagnosis of Pneumocystis jirovecii pneumonia (PJP) and its mixed infection in non-human immunodeficiency virus (HIV) immunosuppressed patients.

Methods

A total of 198 non-HIV immunosuppressed patients with severe pneumonia were enrolled, including 77 PJP patients and 121 patients infected by other pathogens. BALF-mNGS and traditional detection methods were used.

Results

The positive detection rate of various pathogens of BALF-mNGS was higher than that of the conventional methods, especially for mixed pathogens. The sensitivity and specificity of BALF-mNGS for the diagnosis of PJP were 97.40% and 85.12%, respectively. Compared with traditional methods, the sensitivity of BALF-mNGS was significantly higher than that of blood fungal G (BG)/lactate dehydrogenase (LDH) and BALF-microscopy (p<0.05), and its specificity was significantly higher than that of BG/LDH (p<0.05). In addition, the average detection time of BALF-mNGS (32.76 ± 10.32 h) was also significantly shorter than conventional methods (p<0.01), especially for mixed infections that were common in non-HIV immunosuppressed patients. In patients only detected as positive by BALF-mNGS, the underlying diseases mainly manifested as hematological malignancies with agranulocytosis and within 8 months after hematopoietic stem cell or solid organ transplantation.

Conclusions

BALF-mNGS technology is faster, more sensitive, and more comprehensive in detecting P. jirovecii and its mixed infection in immunosuppressed patients.

Clinical impact of pneumothorax in patients with Pneumocystis jirovecii pneumonia and respiratory failure in an HIV-negative cohort

Background

Pneumocystis jirovecii pneumonia (PCP) with acute respiratory failure can result in development of pneumothorax during treatment. This study aimed to identify the incidence and related factors of pneumothorax in patients with PCP and acute respiratory failure and to analyze their prognosis.

Methods

We retrospectively reviewed the occurrence of pneumothorax, including clinical characteristics and results of other examinations, in 119 non-human immunodeficiency virus patients with PCP and respiratory failure requiring mechanical ventilator treatment in a medical intensive care unit (ICU) at a tertiary-care center between July 2016 and April 2019.

Results

During follow up duration, twenty-two patients (18.5%) developed pneumothorax during ventilator treatment, with 45 (37.8%) eventually requiring a tracheostomy due to weaning failure. Cytomegalovirus co-infection (odds ratio 13.9; p = 0.013) was related with occurrence of pneumothorax in multivariate analysis. And development of pneumothorax was not associated with need for tracheostomy and mortality. Furthermore, analysis of survivor after 28 days in ICU, patients without pneumothorax were significantly more successful in weaning from mechanical ventilator than the patients with pneumothorax (44% vs. 13.3%, p = 0.037). PCP patients without pneumothorax showed successful home discharges compared to those who without pneumothorax (p = 0.010).

Conclusions

The development of pneumothorax increased in PCP patient with cytomegalovirus co-infection, pneumothorax might have difficulty in and prolonged weaning from mechanical ventilators, which clinicians should be aware of when planning treatment for such patients.

Adhesins in the virulence of opportunistic fungal pathogens of human

Aspergillosis, candidiasis, and cryptococcosis are the most common cause of mycoses-related disease and death among immune-compromised patients. Adhesins are cell-surface exposed proteins or glycoproteins of pathogens that bind to the extracellular matrix (ECM) constituents or mucosal epithelial surfaces of the host cells. The forces of interaction between fungal adhesins and host tissues are accompanied by ligand binding, hydrophobic interactions and protein-protein aggregation. Adherence is the primary and critical step involved in the pathogenesis; however, there is limited information on fungal adhesins compared to that on the bacterial adhesins. Except a few studies based on screening of proteome for adhesin identification, majority are based on characterization of individual adhesins. Recently, based on their characteristic signatures, many putative novel fungal adhesins have been predicted using bioinformatics algorithms. Some of these novel adhesin candidates have been validated by in-vitro studies; though, most of them are yet to be characterised experimentally. Morphotype specific adhesin expression as well as tissue tropism are the crucial determinants for a successful adhesion process. This review presents a comprehensive overview of various studies on fungal adhesins and discusses the targetability of the adhesins and adherence phenomenon, for combating the fungal infection in a preventive or therapeutic mode.

Estimation of treatment and prognostic factors of pneumocystis pneumonia in patients with connective tissue diseases

Objectives

To investigate short-term prognosis and prognostic factors for connective tissue disease-associated pneumocystis pneumonia (CTD-PCP) using the Japanese nationwide diagnosis procedure combination (DPC) inpatient database.

Methods

The present retrospective cohort study from April 2014 to March 2016 included data of patients with CTD-PCP extracted from the DPC database using the 10^th revision of International Classification of Diseases and Injuries codes.

Results

In 15 901 766 cases registered from 1329 hospitals, 333 of 67 890 patients who were admitted with PCP were diagnosed with CTD-PCP and included in the study. The median age was 71.0 years, and 214 (64.3%), 80 (24.0%), and 29 (8.7%) patients received sulfamethoxazole/trimethoprim (ST) monotherapy and pentamidine-containing and atovaquone-containing therapy, respectively. There were 114 (34.2%) in-hospital deaths, and the 30-day and 60-day in-hospital survival rates after PCP treatment initiation were 66.0% and 53.7%, respectively. Older age (HR 1.06, 95% CI 1.03 to 1.08) and concomitant interstitial lung disease (ILD) (HR 1.65, 95% CI 1.12 to 2.42) were poor prognostic factors. Patients who completed PCP treatment with ST monotherapy had a significantly higher survival rate than those treated with those not treated with ST monotherapy (p=0.015; log-rank test). Pentamidine versus atovaquone as second-line therapy was significantly higher with atovaquone (p=0.012; log-rank test).

Conclusion

Older age and concomitant ILD were poor prognostic factors for CTD-PCP. ST was a reasonable first-line therapy in patients with CTD-PCP, and patients with inadequate response to ST treated with atovaquone tended to have a better prognosis than those treated with pentamidine.

Aetiology and prognostic risk factors of mortality in patients with pneumonia receiving glucocorticoids alone or glucocorticoids and other immunosuppressants: a retrospective cohort study

OBJECTIVES

Long-term use of high-dose glucocorticoids can lead to severe immunosuppression and increased risk of treatment-resistant pneumonia and mortality. We investigated the aetiology and prognostic risk factors of mortality in hospitalised patients who developed pneumonia while receiving glucocorticoid therapy alone or glucocorticoid and other immunosuppressant therapies.

DESIGN

Retrospective cohort study.

SETTING

Six secondary and tertiary academic hospitals in China.

PARTICIPANTS

Patients receiving glucocorticoids who were hospitalised with pneumonia between 1 January 2013 and 31 December 2019.

MAIN OUTCOMES

We analysed the prevalence of comorbidities, microbiology, antibiotic susceptibility patterns, 30-day and 90-day mortality and prognostic risk factors.

RESULTS

CONCLUSIONS: A total of 716 patients were included, with pneumonia pathogens identified in 69.8% of patients. Significant morbidities occurred, including respiratory failure (50.8%), intensive care unit transfer (40.8%) and mechanical ventilation (36%), with a 90-day mortality of 26.0%. Diagnosis of pneumonia occurred within 6 months of glucocorticoid initiation for 69.7% of patients with Cytomegalovirus (CMV) pneumonia and 79.0% of patients with Pneumocystis jirovecii pneumonia (PCP). Pathogens, including Pneumocystis, CMV and multidrug-resistant bacteria, were identified more frequently in patients with persistent lymphocytopenia and high-dose glucocorticoid treatment (≥30 mg/day of prednisolone or equivalent within 30 days before admission). The 90-day mortality was significantly lower for non-CMV viral pneumonias than for PCP (p<0.05), with a similar mortality as CMV pneumonias (24.2% vs 38.1% vs 27.4%, respectively). Cox regression analysis indicated several independent negative predictors for mortality in this patient population, including septic shock, respiratory failure, persistent lymphocytopenia, interstitial lung disease and high-dose glucocorticoid use.Patients who developed pneumonia while receiving glucocorticoid therapy experienced high rates of opportunistic infections, with significant morbidity and mortality. These findings should be carefully considered when determining treatment strategies for this patient population.

Lower Mortality Associated With Adjuvant Corticosteroid Therapy in Non-HIV-Infected Patients With Pneumocystis jirovecii Pneumonia: A Single-Institution Retrospective US Cohort Study

Background

Pneumocystis jirovecii pneumonia (PJP) remains a cause of mortality in HIV-negative patients. The clinical benefit of adjuvant corticosteroids in these patients is uncertain. This study aimed to determine if corticosteroids would reduce mortality in a cohort of HIV-negative PJP patients.

Methods

We examined a retrospective case series of patients diagnosed with PJP at the University of Colorado Hospital between 1995 and 2019. Data were collected in 71 PJP-infected patients. Twenty-eight patients were HIV-negative, and 43 were infected with HIV. We performed bivariate and forward, stepwise multivariable logistic regressions to identify mortality predictors.

Results

Common underlying conditions in HIV-negative patients were hematologic malignancies (28.6%), autoimmune disorders (25.9%), and solid organ transplantation (10.7%). HIV-negative patients had higher rates and durations of mechanical ventilation and intensive care unit stay. Survival was significantly increased in HIV-negative patients receiving adjuvant corticosteroids, with 100% mortality in patients not receiving corticosteroids vs 60% mortality in patients receiving corticosteroids (P = .034). In an adjusted multivariable model, no adjuvant corticosteroid use was associated with higher mortality (odds ratio, 13.5; 95% CI, 1.1–158.5; P = .039) regardless of HIV status.

Conclusions

We found substantial mortality among HIV-negative patients with PJP, and adjuvant corticosteroid use was associated with decreased mortality. Response to corticosteroids is best established in HIV-infected patients, but emerging reports suggest a similar beneficial response in PJP patients without HIV infection. Further prospective studies may establish a more definitive role of the addition of corticosteroids among HIV-negative patients with PJP.

Epidemiology of Pneumocystis jirovecii Pneumonia and (Non-)use of Prophylaxis

Objectives:Pneumocystis jirovecii pneumonia (PCP) is an AIDS-defining illness. In patients with HIV, the benefit of PCP prophylaxis is well-defined when the CD4 T-cell count decreases below 200 cells/μL. In other immunocompromised patients, the value of PCP prophylaxis is not always as well-established. This study aimed to describe the epidemiology of PCP in recent years and assess how many patients with PCP did or did not receive prophylaxis in the month preceding the infection. Material and Methods: A multicenter retrospective study was performed in 3 tertiary care hospital. A list of patients that underwent broncho-alveolar lavage sampling and Pneumocystis jirovecii (PJ) PCR testing was retrieved from the microbiology laboratories. An in-house PJ quantitative PCR (qPCR) was used in each center. A cycle threshold (Ct) value of ≤ 28.5-30 was considered a probable PCP. For patients with a positive PJ qPCR but above this threshold, a predefined case definition of possible PCP was defined as a qPCR Ct value ≤ 34-35 and both of the following criteria: 1. Clinical and radiological features compatible with PCP and 2. The patient died or received PCP therapy and survived. Patient files from those with a qPCR Ct value ≤ 35 were reviewed to determine whether the patient fulfilled the case definition and if PCP prophylaxis had been used in the weeks preceding the PCP. Disease-specific guidelines, as well as hospital-wide guidelines, were used to evaluate if prophylaxis could be considered indicated. Results: From 2012 to 2018, 482 BAL samples were tested. Two hundred and four had a qPCR Ct value ≤ 35 and were further evaluated: 90 fulfilled the definition of probable and 63 of possible PCP while the remaining 51 were considered colonized. Seventy-four percentages of the patients with PCP were HIV-negative. Only 11 (7%) of the 153 patients had received prophylaxis, despite that in 133 (87%) cases prophylaxis was indicated according to guidelines. Conclusion: In regions where HIV testing and treatment is available without restrictions, PCP is mainly diagnosed in non-HIV immunocompromised patients. More than four out of five patients with PCP had not received prophylaxis. Strategies to improve awareness of antimicrobial prophylaxis guidelines in immunocompromised patients are urgently needed.

Prognostic impact of pre-existing interstitial lung disease in non-HIV patients with Pneumocystis pneumonia

BACKGROUND

The increasing incidence of life-threatening Pneumocystis pneumonia (PCP) in non-HIV immunocompromised patients is a global concern. Yet, no reports have examined the prognostic significance of pre-existing interstitial lung disease (ILD) in non-HIV PCP.

METHODS

We retrospectively reviewed the medical records of non-HIV PCP patients with (ILD group) or without (non-ILD group) pre-existing ILD. The clinical features and outcomes of the ILD group were compared with those of the non-ILD group. Cox regression models were constructed to identify prognostic factors.

RESULTS

74 patients were enrolled in this study. The 90-day mortality was significantly higher in the ILD group than in the non-ILD group (62.5% versus 19.0%, p<0.001). In the ILD group, patients with a higher percentage of bronchoalveolar lavage fluid neutrophils had worse outcomes compared to those having a lower percentage (p=0.026). Multivariate analyses revealed that pre-existing ILD (p=0.002) and low levels of serum albumin (p=0.009) were independent risk factors for 90-day mortality. Serum levels of β-d-glucan were significantly reduced after treatment of PCP in both groups, whereas levels of Krebs von den Lungen-6 (KL-6) significantly increased in the ILD group. In the ILD group, the 90-day mortality of patients with increasing KL-6 levels after treatment was significantly higher than those with decreasing levels (78.9% versus 0%, p=0.019).

CONCLUSION

In non-HIV PCP patients, pre-existing ILD is associated with a poorer prognosis. Prophylaxis for PCP is needed in patients with pre-existing ILD under immunosuppression.

Adjunctive corticosteroids may be associated with better outcome for non-HIV Pneumocystis pneumonia with respiratory failure: a systemic review and meta-analysis of observational studies

Background

Evidence supporting corticosteroids adjunctive treatment (CAT) for Pneumocystis jirovecii pneumonia (PCP) in non-HIV patients is highly controversial. We aimed to systematically review the literature and perform a meta-analysis of available data relating to the effect of CAT on mortality of PCP in non-HIV patients.

Methods

We searched Pubmed, Medline, Embase, and Cochrane database from 1989 through 2019. Data on clinical outcomes from non-HIV PCP were extracted with a standardized instrument. Heterogeneity was assessed with the I² index. Pooled odds ratios and 95% confidence interval were calculated using a fixed effects model. We analyzed the impact of CAT on mortality of non-HIV PCP in the whole PCP population, those who had hypoxemia (PaO₂ < 70 mmHg) and who had respiratory failure (PaO₂ < 60 mmHg).

Results

In total, 259 articles were identified, and 2518 cases from 16 retrospective observational studies were included. In all non-HIV PCP cases included, there was an association between CAT and increased mortality (odds ratio, 1.37; 95% confidence interval 1.07–1.75; P = 0.01). CAT showed a probable benefit of decreasing mortality in hypoxemic non-HIV PCP patients (odds ratio, 0.69; 95% confidence interval 0.47–1.01; P = 0.05). Furthermore, in a subgroup analysis, CAT showed a significantly lower mortality in non-HIV PCP patients with respiratory failure compared to no CAT (odds ratio, 0.63; 95% confidence interval 0.41–0.95; P = 0.03).

Conclusions

Our meta-analysis suggests that among non-HIV PCP patients with respiratory failure, CAT use may be associated with better clinical outcomes, and it may be associated with increased mortality in unselected non-HIV PCP population. Clinical trials are needed to compare CAT vs no-CAT in non-HIV PCP patients with respiratory failure. Furthermore, CAT use should be withheld in non-HIV PCP patients without hypoxemia.

MUC1 mediates Pneumocystis murina binding to airway epithelial cells

Previous studies have shown that Pneumocystis binds to pneumocytes, but the proteins responsible for binding have not been well defined. Mucins are the major glycoproteins present in mucus, which serves as the first line of defence during airway infection. MUC1 is the best characterised membrane-tethered mucin and is expressed on the surface of most airway epithelial cells. Although by electron microscopy Pneumocystis primarily binds to type I pneumocytes, it can also bind to type II pneumocytes. We hypothesized that Pneumocystis organisms can bind to MUC1 expressed by type II pneumocytes. Overexpression of MUC1 in human embryonic kidney HEK293 cells increased Pneumocystis binding, while knockdown of MUC1 expression by siRNA in A549 cells, a human adenocarcinoma-derived alveolar type II epithelial cell line, decreased Pneumocystis binding. Immunofluorescence labelling indicated that MUC1 and Pneumocystis were co-localised in infected mouse lung tissue. Incubation of A549 cells with Pneumocystis led to phosphorylation of ERK1/2 that increased with knockdown of MUC1 expression by siRNA. Pneumocystis caused increased IL-6 and IL-8 secretion by A549 cells, and knockdown of MUC1 further increased their secretion in A549 cells. Taken together, these results suggest that binding of Pneumocystis to MUC1 expressed by airway epithelial cells may facilitate establishment of productive infection.

An overview of Pneumocystis jirovecii pneumonia for the African generalist practitioner

Introduction

Pneumocystis jirovecii is the causative organism of Pneumocystis pneumonia (PCP) in humans, which is more common among immunocompromised patients. Classically patients present with fever, non-productive cough, and dyspnoea. In the HIV-infected individuals the symptoms may be subtle at first, but gradually progress over several weeks. In the HIV-uninfected patient, however, the duration of symptoms is shorter and more severe, mainly due to the increased inflammatory response of the HIV-uninfected patient.

Methods

This article focuses on the diagnostic methods and then the management and prophylaxis principles of PCP by reviewing the best current practices and guidelines in Africa.

Conclusion

This overview is presented by clinicians who have experience with PCP and is directed mainly at first-line healthcare providers.

Prognostic effects of clinical and CT imaging features on critically ill patients with interstitial lung disease hospitalized in respiratory intensive care unit

The study aimed to evaluate the clinical and imaging features of critically ill patients with interstitial lung disease (ILD) treated in respiratory intensive care unit (RICU) and assess the prognostic effects of these factors. A total of 160 severe ILD patients admitted to the RICU were finally enrolled in this study. The clinical, imaging and follow-up data of them were studied retrospectively. The in-hospital mortality and total mortality were 43.1% and 63.8% respectively. By multivariate cox regression analysis, shock (OR = 2.39, P = 0.004), pulmonary fibrosis on CT (OR = 2.85, P = 0.002) and non-invasive ventilation (OR = 1.86, P = 0.037) were harmful factors to survivals of critically ill patients with ILD. In contrast, oxygenation index (OR = 0.99, P = 0.028), conventional oxygen therapy (OR = 0.59, P = 0.048) and β-lactam antibiotics use (OR = 0.51, P = 0.004) were protective factors. There is significant difference of survivals between patients with and without fibrosing ILD on CT (Log-rank, p = 0.001). The prognosis of critically ill patients with ILD was poor. Shock, respiratory failure and fibrosing signs on chest CT affected the prognosis. Chest CT was considered as a valuable tool to indicate the prognosis.

Pneumocystis pneumonia in the twenty-first century: HIV-infected versus HIV-uninfected patients

Introduction: Pneumocystis pneumonia (PcP) has classically been described as a serious complication in patients infected with the human immunodeficiency virus (HIV). However, the emerging number of conditions associated with immunosuppression has led to its appearance in other patient populations. Areas covered: This article reviews the most recent publications on PcP in the HIV-infected and HIV-uninfected population, focusing on epidemiology, diagnostic, therapy and prevention. The data discussed here were mainly obtained from a non-systematic review using Medline and references from relevant articles including randomized clinical trials, meta-analyses, observational studies and clinical reviews. Expert opinion: The growing incidence of Pneumocystis infection in the HIV-uninfected population suggests the need for new global epidemiological studies in order to identify the true scale of the disease in this population. These data would allow us to improve diagnosis, therapeutic strategies, and clinical management. It is very important that both patients and physicians realize that HIV-uninfected patients are at risk of PcP and that rapid diagnosis and early initiation of treatment are associated with better prognosis. Currently, in-hospital mortality rates are very high: 15% for HIV-infected patients and 50% in some HIV-uninfected patients. Therefore, adequate preventive measures should be implemented to avoid the high mortality rates seen in recent decades.

Serial change in serum biomarkers during treatment of Non-HIV Pneumocystis pneumonia

BACKGROUND

For patients with non-human immunodeficiency virus (HIV) Pneumocystis pneumonia (PCP), data are limited on serial changes in serum biomarkers and the correlations with clinical outcomes.

OBJECTIVE

This study evaluated serial change in serum biomarkers and clinical outcomes of non-HIV PCP.

METHODS

We retrospectively reviewed data from 63 patients treated for non-HIV PCP at Toho University Omori Medical Center. The patients were classified as survivors and nonsurvivors on the basis of 60-day PCP mortality. The groups were compared for clinical course and levels of serum biomarkers (β-D glucan, Krebs von den Lungen-6 antigen [KL-6], and surfactant protein-D [SP-D]), which were measured at baseline, and 7 days and 14 days after starting treatment. In addition, serial changes in serum biomarkers were analyzed in survivors and nonsurvivors.

RESULTS

There were 14 PCP nonsurvivors and 49 survivors. Biomarker values were not different between groups at baseline. At 7 and 14 days after starting treatment, the proportions of patients with elevated β-D glucan and KL-6 did not significantly differ between groups; however, the proportion of patients with elevated SP-D was significantly lower among survivors than among nonsurvivors (57.1% vs. 100%, p = 0.009; 30% vs. 100%, p < 0.001; respectively). SP-D on day 14 was significantly lower than that at baseline among survivors (99.6 [61.0-190.3] vs. 156 [100.8-283.5]; p = 0.045) but significantly higher among nonsurvivors (974 [744.5-1565] vs. 317 [211-448]; p = 0.03).

CONCLUSION

Serum SP-D value continues to increase after failure of treatment for non-HIV PCP and may thus be associated with outcomes for non-HIV PCP patients.

Risk Factors for Mortality in Pneumocystis jirovecii Pneumonia in Patients with Inflammatory Bowel Disease

Background

Pneumocystis jirovecii pneumonia (PJP) is highly fatal once infection is established. In this study, we investigated the risk of PJP mortality in patients with inflammatory bowel disease (IBD).

Methods

We conducted a retrospective observational study of case data from IBD patients who developed PJP, compiled from 17 collaborating institutions. Parameters such as age, sex, medications used, and blood test results were analyzed to identify risk factors for mortality.

Results

The mortality rate among the 28 IBD patients who developed PJP was 17.9%. A low serum albumin level at the start of IBD treatment was identified as a risk factor for mortality and showed the following association with probability of death (P): P = 1/[1 + exp(-5.5 + 2.4 × Alb). The probability of death exceeded 0.5 when serum albumin was 2.2 g/dL or lower.

Conclusion

Patients with IBD who develop PJP have a high mortality rate and often cannot continue treatment with medication alone. Therefore, it is necessary to pay attention to albumin levels at the start of immunosuppressive therapy when creating a treatment plan.

Pneumocystis jirovecii-related spontaneous pneumothorax, pneumomediastinum and subcutaneous emphysema in a liver transplant recipient: a case report

BACKGROUND

Pneumocystis pneumonia (PCP) is a common opportunistic infection caused by Pneumocystis jirovecii. Its incidence at 2 years or more after liver transplant (LT) is < 0.1%. PCP-related spontaneous pneumothorax and/or pneumomediastinum is rare in patients without the human immunodeficiency virus, with an incidence of 0.4-4%.

CASE PRESENTATION

A 65-year-old woman who had split-graft deceased-donor LT for primary biliary cirrhosis developed fever, dyspnea and dry coughing at 25 months after transplant. Her immunosuppressants included tacrolimus, mycophenolate mofetil, and prednisolone. PCP infection was confirmed by molecular detection of Pneumocystis jirovecii,in bronchoalveolar lavage. On day-10 trimethoprim-sulphamethoxazole, her chest X-ray showed subcutaneous emphysema bilaterally, right pneumothorax and pneumomediastinum. Computed tomography of the thorax confirmed the presence of right pneumothorax, pneumomediastinum and subcutaneous emphysema. She was managed with 7-day right-sided chest drain and a 21-day course of trimethoprim-sulphamethoxazole before discharge.

CONCLUSION

Longer period of PCP prophylaxis should be considered in patients who have a higher risk compared to general LT patients. High index of clinical suspicion, prompt diagnosis and treatment with ongoing patient reassessment to detect and exclude rare, potentially fatal but treatable complications are essential, especially when clinical deterioration has developed.